Nozzle with a first passage and second passages surrounding the first passage and nozzle arrangement

Abstract

The invention relates to a nozzle (1.1, 1.2, 1.3) having a first nozzle section (2.1) in the form of a truncated cone, a first passage that forms a first nozzle opening (5.1) in a top surface (3.1) of the first nozzle section (2.1), and second passages that form second nozzle openings (5.2) in the lateral surface (3. 3) of the first nozzle section (2.1), wherein the second passages each have a passage axis (9) tilted relative to a parallel axis (8) parallel to the centre axis (7) of the nozzle (1.1, 1.2, 1.3). The invention also relates to a nozzle arrangement (20) having a supply line (22), a supply opening, at least one nozzle (1.1, 1.2, 1.3, 1.4) that has an inlet opening (16) and at least one nozzle holder (23) with a receptacle (25), wherein the nozzle (1.1, 1.2, 1.3, 1.4) has a recess (26) for contact with the supply line (22) and wherein the nozzle (1.1, 1.2, 1.3, 1.4) is detachably held and centred on the receptacle (25) and the nozzle holder (23) is detachably held on the supply line.

Description

[0001] Nozzle with a first passage and second passages surrounding the first passage and nozzle arrangement

[0002] Technical area

[0003] The present invention relates to a nozzle for cleaning a filter element by means of a fluid flow, having a first passage and second passages surrounding the first passage. The present invention further relates to a nozzle arrangement comprising a pipe and a nozzle attached thereto.

[0004] Background of the invention

[0005] Nozzles are already known from the state of the art with a variety of geometries and for a variety of purposes, in particular as air nozzles or liquid nozzles.

[0006] When cleaning filter elements, such as cartridge filters, pocket filters, flat filters, or cylindrical filters, a targeted fluid flow is used to remove a filter cake from the filter element. For example, cleaning is performed by backflow, as is known from DE 4423 439 A1. However, cleaning can also be performed by directing the fluid across a surface of the filter element on which the filter cake is deposited, in order to shear off the filter cake. Cleaning a filter by means of an air flow is also known, for example, from DE 20 2013 100 593 LJ1.

[0007] In the cleaning processes mentioned, particularly with cylindrical filter elements in which the fluid flow is directed transversely to an inner surface and in the direction of the central axis of the cylindrical filter element, nozzles are used to generate or direct a specific fluid flow. For example, pulses of air are released from a compressed air tank or a compressed air line using solenoid valves and directed through the nozzle onto the filter element. The disadvantage here is that the flow is often not sufficiently uniform across the surface to be cleaned and / or the impulse is too low to clean the entire surface. In particular, a sufficient impulse or a sufficient shearing effect can no longer be achieved beyond a certain distance from the nozzle.

[0008] Another disadvantage is that known nozzles are often permanently mounted in a corresponding nozzle arrangement and are then difficult to remove from the supply line or from the nozzle arrangement, for example for maintenance or replacement.

[0009] Description of the invention

[0010] Based on this situation, it is an object of the present invention to propose a nozzle or nozzle arrangement by means of which the fluid guidance during cleaning of a filter element can be improved, in particular by fluid flow transversely to a surface of the filter element, and which is easy to handle.

[0011] The object of the invention is achieved by the features of the independent main claims. Advantageous embodiments are specified in the subclaims. To the extent technically feasible, the teachings of the subclaims can be combined arbitrarily with the teachings of the main and subclaims.

[0012] Advantages of the claimed aspects of the invention are explained below, and preferred modified embodiments of the aspects of the invention are described further below. Explanations, particularly regarding advantages and definitions of features, are essentially descriptive and preferred, but not limiting, examples. If an explanation is limiting, this will be expressly stated.

[0013] Where elements are designated by numbering, for example “first element”, “second element” and “third element”, this numbering is intended purely to differentiate the designation and does not represent any dependency of the elements on one another or a mandatory order of the elements. This means in particular that, for example, a device or a method does not have to have a “first element” in order to be able to have a “second element”. The device or method can also have a “first element” and a “third element” without necessarily having a “second element”. Multiple units of an element with a single numbering can also be provided, for example multiple “first elements”.

[0014] According to a first aspect of the invention, the object is achieved by a nozzle for cleaning a filter element by means of a fluid flow, comprising at least one first nozzle section designed as a hollow truncated cone, at least one first passage, wherein the first passage forms a first nozzle opening in a cover surface of the first nozzle section, and a plurality of second passages surrounding the first passage, wherein the second passages form second nozzle openings in the lateral surface of the first nozzle section, wherein the second passages each have a passage axis tilted with respect to a parallel axis parallel to a central axis of the nozzle for imposing a helical flow contour on the fluid flow.

[0015] A nozzle is understood to be a device with an inlet side or an inlet cross-section and an outlet side or an outlet cross-section, wherein a fluid flows into the nozzle at the inlet side or through the inlet cross-section and flows out of the nozzle at the outlet side or through the outlet cross-section. The flow properties of the fluid flow between the inlet side / inlet cross-section and the outlet side / outlet cross-section, and in particular by means of nozzle openings that form the outlet side or the outlet cross-section, are influenced. In particular, the fluid flow is influenced with regard to the flow contour, the flow velocity and the mass flow. The flow contour is understood to be the sum of the courses of the spatial positions and velocities through which the individual fluid particles pass. A fluid is, in particular, air, another gas or a liquid such as water.

[0016] A filter element is designed, for example, as a cylindrical filter element, as a pocket filter, as a cartridge filter or as a flat filter and comprises a filter medium such as a fleece or the like that is permeable to part of a fluid flow to be filtered and impermeable to another part of the fluid flow to be filtered. For example, dust and particles are filtered out of an air flow in this way. The retained parts of the fluid flow to be filtered form a filter cake on and / or in the filter medium on a front side of the filter medium over time or with the amount of fluid flowing through the filter medium, which filter cake increases the flow resistance for the fluid. Cleaning in this case comprises at least partially removing the filter cake from the surface of the filter medium in order to (again) reduce the flow resistance.

[0017] A hollow truncated cone is defined as a geometry that forms a coaxial connecting surface between a round base surface and a round top surface that is smaller than the base surface. The hollow design creates an interior space on the truncated cone that geometrically corresponds to the outer contour, with the interior space being free of material. The truncated cone thus forms a wall that forms the outer surface of the outer contour and the inner surface of the inner contour. In particular, the interior space on the base surface forms an inlet opening of the truncated cone for admitting a fluid flow.

[0018] A penetration is understood to be a recess through a material, in particular a wall or multiple walls, the walls of which are formed in particular parallel to one another and in particular parallel to a penetration axis. A penetration can also become larger or smaller in cross-section along the penetration axis, so that the walls are then, for example, not exactly parallel to one another, but for example almost parallel. A penetration is defined in particular by a direction of the penetration axis and a penetration geometry. Any desired penetration geometries are possible, in particular with regard to the cross-section, but a penetration is preferably formed as a bore with a round cross-section and a bore diameter.

[0019] A helical flow contour is determined by the fact that individual fluid particles follow a helical path. This imparts a swirl to the flow contour or individual fluid particles.

[0020] The solution to the problem described above now comprises the technical teaching that a first nozzle opening is provided centrally on the cover surface for ejecting a core flow, and that a plurality of second nozzle openings are provided around the first nozzle opening on the jacket surface for ejecting an outer flow. The first nozzle opening or the first passage provided for forming the first nozzle opening is preferably arranged concentrically with the central axis of the nozzle, i.e., has a passage axis concentric with the central axis and walls parallel to the central axis. The flow direction of the core flow thus points straight out of the nozzle. The second passages are each tilted, so that the outer flow has an imposed swirl or an imposed flow direction towards the helical shape.Advantageously, the core flow, which without the outer flow would fan out in a funnel shape relatively close to the nozzle and thus only act on the surface of the filter element with greatly reduced momentum, can be constricted or bundled and thus directed by the helical outer flow. By imposing the helical flow contour, the outer flow prevents the outer flow from fanning out, and the outer flow acts on the entire flow contour in such a way that the flow contour is constricted / bundled overall and spatially stabilized. A flow contour stabilized in this way can then act more precisely, particularly at a greater distance from the nozzle on the surface of the filter element, and apply an increased momentum component to a desired area of ​​the surface.In particular, the precise geometric design of the nozzle, in particular the diameter ratio of the first passage to the second passages, the number and arrangement of the second passages, and the selection of tilt angles by which the second passages are tilted relative to the parallel axes, make it possible to precisely adapt the flow contour to specific filter elements, particularly in terms of their diameter or the development of the diameter over the axial distance from the nozzle. The flow contour then precisely fills, for example, a cylindrical filter element, and a particularly favorable shear is achieved on the inner surface of the cylindrical filter element.In simple terms, tilting the second passages enables a particularly stable flow contour and simple and precise control over the directional characteristic of the nozzle, so that the directional characteristic can be precisely selected for a specific application.

[0021] In one embodiment, the second passages are arranged on a circular path concentric with the center axis of the nozzle. The flow contour is then advantageously axisymmetric about the center axis of the nozzle or about a core flow concentrically aligned therewith and is therefore particularly stable. Furthermore, such a flow contour is particularly suitable for cleaning a cylindrical filter element. Such a cylindrical shape is a standard geometry for filter elements when filtering air streams in industrial applications. Furthermore, the arrangement of the second passages on a circular path concentric with the center axis on the nozzle, the base body of which, formed at least by the first nozzle section, has a round cross-section, creates an even pressure distribution within the nozzle, so that the material load on the nozzle is kept low.

[0022] In one embodiment, the first nozzle section has a concavely tapered outer surface. A concave taper of the outer surface or of the truncated cone is understood to mean that the outer surface is not linearly tapered in the axial direction of the truncated cone from the base surface to the top surface, but rather tapers sharply in a concave manner. In this respect, a truncated cone is also understood to mean a geometry whose outer surface has a concavity (and / or convexity) of the outer surface compared to a geometrically ideal truncated cone. Advantageously, the concave taper stretches the second nozzle openings, so that their cross-section is enlarged and the proportion of the outer flow in the overall flow contour is increased compared to a linearly tapered outer surface.

[0023] In a further embodiment, the nozzle has a second nozzle section, designed as a hollow cylinder, adjoining a base surface of the first nozzle section. The nozzle is then extended toward its inlet side and has an interior region in the second nozzle section within which the fluid flow can adjust and stabilize in a laminar manner, independent of upstream components, before the fluid reaches the nozzle openings. This continues to enable a stable and uniform, or axisymmetric, flow.

[0024] In a preferred embodiment of the aforementioned embodiment, the second passages protrude radially outward from the inside into an outer wall of the second nozzle section to form a contour on an inner side of the outer wall. The second passages therefore overlap with the wall of the second nozzle section, but without intersecting its outer contour. Groove-shaped recesses are thus created on the inner side of the wall of the second nozzle section. The imposition of a spin or a helical flow contour then advantageously already takes place within the nozzle, namely in the second nozzle section, comparable to the imposition of a spin on a bullet in a rifle by rifling arranged in the rifle barrel. In this way, the flow contour is further stabilized.In the embodiment described above, the second nozzle section particularly preferably has a recess on a base surface for contact with a cylindrical contour running at an angle to the central axis of the nozzle, and in particular a collar. The second nozzle section can then be placed in a contour-matching manner against an opening in a side wall of a tubular supply line, so that a particularly flow-optimized and uninterrupted, in particular leak-tight, transition is formed between the supply line and the nozzle. The nozzle can be positioned with its central axis, for example, perpendicular to the supply line or at any other angle. By forming a collar, a contact surface of the nozzle on the supply line is enlarged, for example for providing sealing means.

[0025] Particularly preferably, such a collar can also be used to hold the nozzle to the supply line, in particular for a positive fit. The collar is preferably formed along the recess to fit the cylinder contour or forms the contour itself.

[0026] In one embodiment, the passage axes of the second passages are each arranged tilted by a first tilt angle about a first transverse axis that is perpendicular to the parallel axis and intersects the center axis of the nozzle. The first tilt angle is preferably 0 to 45°, particularly preferably 23°. The first tilt angle is, for example, 1°, 2°, 3°, 5°, 10°, 15°, 20°, 23°, 25°, 30°, 35°, 40°, 45° or an angle lying between these values. By providing the first tilt angle, in particular the pitch of the helical contour of the outer flow is influenced. The selected first tilt angle advantageously achieves a favorable constriction of the flow contour and a favorable range of the flow contour, i.e. a sufficient distance from the nozzle at which the flow contour is still stable.

[0027] In a further embodiment, the penetration axes of the second penetrations are each arranged tilted by a second tilt angle about a second transverse axis perpendicular to the parallel axis and perpendicular to the first transverse axis. The second tilt angle is preferably 0 to 90°, particularly preferably 45°. The second tilt angle is, for example, 1°, 2°, 3°, 5°, 10°, 15°, 20°, 25°, 30°, 35°, 40°, 45°, 50°, 55°, 60°, 65°, 70°, 75°, 80°, 85°, 90° or an angle lying between these values. The selected second tilt angle influences the diameter or the development of the diameter over the axial distance from the nozzle of the flow contour. Advantageously, the nozzle can be adjusted in the selected range of the second tilt angle for cleaning the inner surface in the axial direction of a plurality of cylindrical filter elements, in particular for a plurality of length-to-diameter ratios of such cylindrical filter elements.

[0028] Preferably, a taper ratio between an inlet cross-section and an outlet cross-section of the nozzle is between 1:1 and 3:1. An inlet cross-section is formed, in particular, by an inlet opening formed by the interior space at the base surface of the first nozzle section or the second nozzle section. An outlet cross-section results from the sum of the cross-sections of all nozzle openings. With these ratios, a favorable ratio between the flow velocity and the mass flow of the air flow is achieved for cleaning filter elements by means of air blasts from a pressure tank or a pressure line.

[0029] In one embodiment, the first passage is round and has a diameter of 1 to 70% of a nozzle diameter. The nozzle diameter is understood to be the maximum outer diameter of the nozzle. In a further embodiment, which is preferably combined with this embodiment, the second passages are also each round and have a diameter of 1 to 70% of the nozzle diameter. With the stated diameters, a favorable flow contour is achieved for cleaning conventional cylindrical filter elements for air purification in industrial applications. In addition, a favorable ratio of the core flow to the outer flow is then present for a stable flow contour with a favorable range. An odd number of second passages is preferably provided. This avoids point symmetries, which can be accompanied by mutually canceling effects.

[0030] In a further embodiment, the nozzle has a plurality of third passages, each of which intersects an inner contour of the first passages and is parallel to the center axis of the nozzle. The third passages form a contour of the first passage, thereby concentrating and directing the core flow. This advantageously achieves a particularly well-directed and stable flow contour.

[0031] Preferably, a nozzle according to the above-described aspect of the invention is manufactured using an additive manufacturing process. Advantageously, one or more tilt angles can be specifically adjusted for cleaning a specific filter element and manufactured with minimal effort. In particular, additive manufacturing enables complex nozzle geometries with minimal manufacturing effort.

[0032] The object is further achieved by a nozzle arrangement for cleaning a filter element by means of a fluid flow, comprising at least one tubular supply line with a supply line opening in a jacket surface of the supply line, at least one nozzle designed as a hollow body with a base surface, wherein the nozzle has an inlet opening in the base surface, and at least one nozzle holder with a receptacle for the nozzle, wherein the nozzle has a recess on the base surface for contact with the jacket surface of the supply line in such a way that the inlet opening rests against the supply line and is aligned with the supply line opening, and wherein the nozzle is releasably held and centered on the receptacle of the nozzle holder, and the nozzle holder is releasably held on the supply line. The supply line is connected, for example, to a pressure tank or a pressure line.

[0033] Tubular is defined as a profile geometry that extends primarily in a longitudinal direction. The profile can be any hollow profile and, for example, round or polygonal. The cross-section of the profile can be constant or variable along its longitudinal extent.

[0034] With regard to the nozzle, the terms used in the above description of the nozzle arrangement are to be understood as they are understood with regard to the nozzle described above.

[0035] The solution to the problem described above therefore comprises the teaching that a nozzle is held on the supply line by means of a nozzle holder, wherein both the nozzle on the nozzle holder and the nozzle holder on the supply line are each releasably held. The nozzle holder is designed such that the nozzle is centered relative to the nozzle holder or relative to the supply line. For example, appropriately shaped centering means are provided on the nozzle and the nozzle holder for this purpose. By means of the centering, alignment of the inlet opening of the nozzle with the supply line opening is achieved. By means of the nozzle arrangement, it is also advantageously possible for a nozzle to be arranged on the supply line with little effort and minimal tool use. In this way, the nozzle arrangement can be easily disassembled and then reassembled for changing a nozzle for maintenance, changing a nozzle geometry or for cleaning.The nozzle arrangement is also designed to be simple and cost-effective to manufacture. The nozzle arrangement described above also allows for free positioning of the nozzle on the pipeline depending on the position of a supply opening.

[0036] Thanks to the above-described design of the nozzle assembly, the nozzle is securely held in place on the nozzle holder or on the supply line in all spatial directions, and in particular, is secured against rotation. This prevents the nozzle from slipping and / or twisting during operation.

[0037] The supply line opening is preferably aligned transversely, in particular exactly perpendicularly, to a central axis of the supply line or is oriented at an angle to this central axis of the supply line. The recess arranged on the base surface of the nozzle is oriented at a corresponding angle for contact with the outer surface of the supply line.

[0038] In a particularly preferred embodiment of the invention, the nozzle of the nozzle arrangement is designed with a nozzle in accordance with the solution to the problem described above. The advantages described above are then achieved accordingly for the nozzle arrangement. In particular, such a nozzle can then be positioned on the supply line in such a way that the flow contour is precisely positioned relative to the filter element for cleaning the surface of the filter element.

[0039] In a further preferred embodiment, the nozzle is held in a form-fitting manner on the nozzle holder and can in particular be inserted into the recess from an inside of the nozzle holder that is concealed by the supply line. As a result of the form-fitting manner, the nozzle is particularly easily fastened to the nozzle holder and centered. The form-fitting arrangement is particularly preferably designed such that the nozzle assumes a centered position therein. By means of a design in which the nozzle can be inserted into the recess from an inside of the nozzle holder that is concealed by the supply line, the supply line enables the nozzle to be easily fixed in the receptacle in order to achieve centering and securing. During assembly / disassembly of the nozzle arrangement, the nozzle is then inserted into the recess or removed from the receptacle when the nozzle holder is detached from the supply line.

[0040] In a preferred embodiment of the aforementioned embodiment, the nozzle has a collar and is held positively to the nozzle holder by means of the collar. Such a collar enables a centered and secure holding of the nozzle on the nozzle holder in a simple manner, in particular when the nozzle can be inserted into the recess from an inside of the nozzle holder covered by the supply line and the collar then engages behind the nozzle holder. A collar can also be used, for example, as a sealing surface and / or to accommodate a

[0041] sealant.

[0042] In a preferred embodiment, the nozzle holder is held firmly on the supply line and, in particular, clamped to the supply line in a clamp-like manner. This allows for secure and quickly releasable retention of the nozzle holder. Furthermore, since the nozzle can be inserted into the nozzle holder from the inside of the nozzle holder, the nozzle inserted into the nozzle holder allows for easy and unobstructed positioning of the nozzle holder on the supply line.

[0043] In one embodiment of the aforementioned embodiment, the nozzle holder is designed to be hinged or bendable and can be held in a folded / bent position by means of connecting means and can be clamped onto the supply line. The nozzle holder is then also in a folded / bent position in one piece and has no loose parts. Furthermore, positioning the nozzle holder on the supply line is particularly easy when the nozzle holder is folded / bent or partially folded / bent, and holding the nozzle holder on the supply line is particularly easy by closing the connecting means. If the nozzle holder is designed to be hinged / bent through a sufficient opening angle, positioning the nozzle holder on the supply line in a radial direction is also possible, so that the necessary installation space is kept to a minimum.

[0044] In one embodiment, a plurality of nozzles are arranged on the supply line by means of a corresponding plurality of nozzle holders. The teaching of the described solution can then be used for more than one nozzle in a single supply line. In particular, several filter elements can be cleaned simultaneously, or a single filter element can be cleaned using several nozzles. Different nozzles with different geometries or different flow contours can be used simultaneously. Furthermore, the nozzle preferably has a projection on the inlet opening that projects into the supply line opening. In this way, simple and reliable centering of the nozzle relative to the supply line or of the inlet opening relative to the supply line opening is achieved, and alignment of the openings with one another is ensured.Insofar as the inlet opening and the supply opening are round, an additional anti-twist device is provided, for example by a corresponding form fit between the nozzle and the nozzle holder.

[0045] Short description of the drawings

[0046] The invention will be explained in more detail below with reference to preferred embodiments and the accompanying drawings. The term "figure" is abbreviated to "Fig."

[0047] The drawings show

[0048] Fig. 1a is a perspective view of a nozzle according to one aspect of the invention according to a first embodiment;

[0049] Fig. 1 b the nozzle according to Fig. 1a in a side view;

[0050] Fig. 1c the nozzle according to Fig. 1a and Fig. 1b in plan view;

[0051] Fig. 1d shows the nozzle according to Fig. 1a, Fig. 1b and Fig. 1c in a further perspective view;

[0052] Fig. 2a is a perspective view of a nozzle according to one aspect of the invention according to a second embodiment;

[0053] Fig. 2b the nozzle according to Fig. 2a in a side view;

[0054] Fig. 2c the nozzle according to Fig. 2a and Fig. 2b in plan view;

[0055] Fig. 2d shows the nozzle according to Fig. 2a, Fig. 2b, and Fig. 2c in a further perspective view; Fig. 3 shows a schematic representation of a nozzle arrangement according to one aspect of the invention according to an embodiment;

[0056] Fig. 4a is a side view of a nozzle and a nozzle holder for a nozzle arrangement according to Fig. 3;

[0057] Fig. 4b is a perspective view of a nozzle holder according to Fig. 3 or Fig. 4a; and

[0058] Fig. 4c is a perspective view of a nozzle according to Fig. 3 or Fig. 4a.

[0059] Detailed description of the drawings

[0060] The described embodiments are merely examples that can be modified and / or supplemented in a variety of ways within the scope of the claims. Each feature described for a specific embodiment can be used independently or in combination with other features in any other embodiment. Each feature described for an embodiment of a specific claim category can also be used correspondingly in an embodiment of a different claim category.

[0061] Figures 1a to 1d show a first embodiment of a nozzle 1.1. The nozzle 1.1 comprises a first nozzle section 2.1 and a second nozzle section 2.2. The first nozzle section 2.1 is designed as a hollow truncated cone with a cover surface 3.1 and a base surface 3.2 (shown in a hidden manner). An almond surface 3.3 of the truncated cone is designed to taper concavely from the base surface 3.2 to the cover surface 3.1. The second nozzle section 2.2 is designed as a hollow cylinder and adjoins the base surface 3.2 of the first nozzle section 2.1 with a cover surface 4.1 (shown in a hidden manner). Furthermore, the second nozzle section 2.2 for its part has a base surface 4.2 (shown in a hidden manner) and a lateral surface 4.3. The nozzle 1.1 has a first passage, which forms a first nozzle opening 5.1 in the cover surface 3.1 of the first nozzle section 2.1. Furthermore, the nozzle 1.1 has five second passages which are arranged on a circular line around the first passage and form second nozzle openings 5.2 in the lateral surface 3.3. The first passage has a passage axis which runs concentrically with a central axis 7 of the nozzle 1.1. Seven third passages which overlap with the first passage are also formed on the first passage and form a contour with grooves 6.1 on the inner walls of the first passage. The second passages have passage axes 9 which are each tilted relative to a parallel axis 8 which is parallel to the central axis 7 of the nozzle 1.1. The passage axes 9 of the second passages are tilted by a first tilt angle α about a first transverse axis 10 which is perpendicular to the parallel axis 8 and intersects the central axis 7 of the nozzle 1.1.Furthermore, the penetration axes 9 of the second penetrations are each tilted by a second tilt angle β about a second transverse axis 11 perpendicular to the parallel axis 8 and perpendicular to the first transverse axis 10. Fig. 1d shows a view in line with one of the second penetrations, from which the course of the penetration axis 9 of this second penetration can be seen in more detail. Furthermore, it can be seen from Fig. 1a that the second penetrations 5.2 project radially into an inner circumferential surface of the second nozzle section 2.2 and form a contour with grooves 6.2 there.

[0062] Figures 2a to 2d show a second embodiment of a nozzle 1.2 which corresponds to nozzle 1.1 in its essential features and differs from nozzle 1.1 in particular in that it has seven instead of five second passages or second nozzle openings 5.2. The second passages have a cross-section of reduced size. Furthermore, no third passages are provided on nozzle 1.2. The first passage therefore has a smooth inner wall. A repeated description of the similar features of nozzles 1.1 and 1.2 is omitted. Figure 3 shows a nozzle arrangement 20 in a schematic representation with a pressure tank 21, a supply line 22 connected to pressure tank 21 and two nozzles 1.3 and 1.4 arranged on supply line 22. The nozzles 1.3, 1.4 are arranged above cylindrical filter elements 12 and are designed to clean an inner surface of the filter elements 12. The nozzle 1.3 is designed in its essential features corresponding to the nozzles 1.1, 1.2 according to Figures 1a to 2d and therefore has a bundled flow contour 13 which in its diameter essentially corresponds to the inner diameter of the cylindrical filter element 12 and is thus designed particularly advantageously for shearing off a filter cake on the inner circumferential surface of the filter element 12. In the flow contour 13, the helical shape is shown by corresponding directional arrows. By bundling / constricting the flow contour 13, the flow contour 13 is designed to be stable approximately over the entire length of the filter element 12. The nozzle 1.4, on the other hand, is not designed according to the invention but according to the prior art and has a nozzle 1 which is located shortly behind the nozzle 1.4 extending and widely fanned out flow contour 14, by means of which a targeted shearing of a filter cake on the inner surface of the filter element 12 is only possible insufficiently or with very high pressures in the pressure tank 21.

[0063] Figures 4a to 4c show the design of a nozzle 1.3 held on the supply line 22 by means of a nozzle holder 23, or the nozzle holder 23 and the nozzle 1.3 are each free-standing. The nozzle holder 23 is designed as a bendable, clamp-shaped component and can be clamped onto a round supply line 22 by means of connecting means 24 designed as clamping means. The nozzle holder 23 further has a receptacle 25 for the nozzle 1.3, which is formed on the one hand by a round recess 25.1 for inserting the nozzle 1.3 from an inner side of the nozzle holder 23 and on the other hand by a hexagonal recess 25.2 for positive engagement with a collar 15 of the nozzle 1.3. The recess 25.2 and the collar 15 can also have any other geometries that correspond to one another for positive engagement.

[0064] The nozzle 1.3 has a collar 15 on the base surface 4.2 with a hexagonal outer contour for positive engagement with the recess 25.2. The collar 15 forms a recess 26 for contact with the outer surface of the supply line 22, such that the collar 15 is in the

[0065] Nozzle holder 23 inserts the nozzle 1 .3 inserted from the inside into the inner contour 23.1 of the nozzle holder 23. The nozzle 1 .3 further has a projection 27 projecting into this inner contour 23.1 of the nozzle holder 23, which surrounds an inlet opening 16 of the nozzle 1 .3. As can be seen in Figure 4a, the projection 27 projects into the nozzle holder 23 and is thus designed to engage in a supply opening (not shown), thus ensuring the alignment of the inlet opening 16 with the supply opening and centering the openings relative to one another.

[0066] Overall, the nozzle 1.3 is held in a fixed position and secured against rotation on the nozzle holder 23. The nozzle 1.3 is held in the recess 25, particularly by the supply line 22, when the nozzle holder 23 is mounted on the supply line 22.

[0067] List of reference symbols Nozzle Nozzle Nozzle Nozzle First nozzle section Second nozzle section Cover surface of the first nozzle section Base surface of the first nozzle section Shell surface of the first nozzle section Cover surface of the second nozzle section Base surface of the second nozzle section Shell surface of the second nozzle section First nozzle opening Second nozzle opening Groove Groove Center axis of the nozzle Parallel axis Passage axis of the second passage First transverse axis Second transverse axis Filter element Flow contour Flow contour Collar Inlet opening Nozzle arrangement Pressure tank Supply line Nozzle holder Connecting means 25 Holder

[0068] 25.1 Recess of the holder

[0069] 25.2 Recess of the holder

[0070] 26 Recess for contact with the outer surface of the supply line 27 Projection a first tilt angle ß second tilt angle

Claims

Patent claims 1. A nozzle (1.1, 1.2, 1.3) for cleaning a filter element (12) by means of a fluid flow, comprising at least one first nozzle section (2.1) designed as a hollow truncated cone; at least one first passage, wherein the first passage forms a first nozzle opening (5.1) in a cover surface (3.1) of the first nozzle section (2.1); and a plurality of second passages surrounding the first passage, wherein the second passages form second nozzle openings (5.2) in the outer surface (3.3) of the first nozzle section (2.1); wherein the second passages each have a passage axis (9) tilted relative to a parallel axis (8) parallel to the central axis (7) of the nozzle (1.1, 1.2, 1.3) for imposing a helical flow contour (13) on the fluid flow.

2. Nozzle (1.1, 1.2, 1.3) according to claim 1, wherein the second passages are arranged on a circular path concentric with the central axis (7) of the nozzle (1.1, 1.2, 1.3).

3. Nozzle (1.1, 1.2, 1.3) according to claim 1 or 2, wherein the first nozzle section (2.1) has a concavely tapered outer surface (3.3).

4. Nozzle (1.1, 1.2, 1.3) according to one of the preceding claims, comprising a nozzle (1.1, 1.2, 1.3) which is connected to a base surface (3.2) of the first Nozzle section (2.1) adjoining the second nozzle section (2.2) designed as a hollow cylinder.

5. Nozzle (1.1, 1.2, 1.3) according to claim 4, wherein the second passages project radially outward from the inside into an outer wall of the second nozzle section (2.2) to form a contour on an inner side of the outer wall.

6. Nozzle (1.1, 1.2, 1.3) according to claim 4 or 5, wherein the second nozzle section (2.2) has a recess (26) on a base surface (4.2) for contact with a cylinder contour extending at an angle to the central axis (7) of the nozzle (1.1, 1.2, 1.3) and in particular a collar (15).

7. Nozzle (1.1, 1.2, 1.3) according to one of the preceding claims, wherein the passage axes (9) of the second passages are each arranged tilted by a first tilt angle (α) about a first transverse axis (10) which is perpendicular to the parallel axis (8) and intersects the central axis (7) of the nozzle (1.1, 1.2, 1.3), wherein in particular the first tilt angle (α) is 0 to 45°, particularly preferably 23°.

8. Nozzle (1.1, 1.2, 1.3) according to one of the preceding claims, wherein the passage axes (9) of the second passages are each arranged tilted by a second tilt angle (ß) about a second transverse axis (11) which is perpendicular to the parallel axis (8) and perpendicular to the first transverse axis (10), wherein in particular the second tilt angle (ß) is 0 to 90°, particularly preferably 45°.

9. Nozzle (1.1, 1.2, 1.3) according to one of the preceding claims, wherein a taper ratio between an inlet cross-section and an outlet cross-section of the nozzle (1.1, 1.2, 1.3) is between 1:1 and 3:

1.

10. Nozzle (1.1, 1.2, 1.3) according to one of the preceding claims, wherein the first passage is round and has a diameter of 1 to 70% of a nozzle diameter and / or wherein the second passages are each round and have a diameter of 1 to 70% of the nozzle diameter.

11. Nozzle (1.1, 1.2, 1.3) according to one of the preceding claims, comprising a plurality of third passages each intersecting an inner contour of the first passage and parallel to the central axis (7) of the nozzle (1.1, 1.2, 1.3).

12. Nozzle arrangement (20) for cleaning a filter element (12) by means of a fluid flow, comprising a tubular supply line (22) with a supply line opening in a lateral surface of the supply line (22); at least one nozzle (1.1, 1.2, 1.3, 1.4) designed as a hollow body with a base area (4.2), wherein the nozzle (1.1, 1.2, 1.3, 1.4) has an inlet opening (16) in the base area (4.2); and at least one nozzle holder (23) with a receptacle (25) for the nozzle (1.1, 1.2, 1.3, 1.4); wherein the nozzle (1.1, 1.2, 1.3, 1.4) has a recess (26) on the base surface (4.2) for engagement with the lateral surface of the supply line (22), such that the inlet opening (16) bears against the supply line (22) and is aligned with the supply line opening; and wherein the nozzle (1.1, 1.2, 1.3, 1.4) is releasably held and centered on the receptacle (25) of the nozzle holder (23), and the nozzle holder (23) is releasably held on the supply line.

13. Nozzle arrangement (20) according to claim 12, wherein the nozzle (1.1, 1.2, 1.3) is designed according to one of claims 1 to 11.

14. Nozzle arrangement (20) according to claim 12 or 13, wherein the nozzle (1.1, 1.2, 1.3, 1.4) is held in a form-fitting manner on the nozzle holder (23) and can be inserted into the recess (25) in particular from an inner side of the nozzle holder (23) concealed by the supply line (22).

15. Nozzle arrangement (20) according to claim 14, wherein the nozzle (1.1, 1.2, 1.3, 1.4) has a collar (15) and is held positively on the nozzle holder (23) by means of the collar (15).

16. Nozzle arrangement (20) according to one of claims 12 to 15, wherein the nozzle holder (23) is held force-fittingly on the supply line (22) and in particular is clamped onto the supply line (22) in a clamp-like manner.

17. Nozzle arrangement (20) according to claim 16, wherein the nozzle holder (23) is designed to be hinged or bendable and is designed to be held in a folded / bent position by means of connecting means (24) and to be clamped onto the supply line (22).

18. Nozzle arrangement (20) according to one of claims 12 to 17, wherein the nozzle (1.1, 1.2, 1.3, 1.4) has a projection (27) on the inlet opening (16) which projects into the supply opening.

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